The Tejon Pass corridor has been an important link between the San Joaquin Valley and Southern California since pre-European days. It is now dominated by Interstate 5, combined with Highway 99.

Many people call the route simply "the Grapevine", but technically Grapevine Canyon is the location of the steep northern grade. Fort Tejon was strategically located at the top of this grade, just below the actual pass. For the continuation of this corridor in Los Angeles County see Interstate 5 to Tejon Pass.